Recent demonstrations of ring and disk silicon micro-resonators continue to build the case for these devices as compact, low power and high-speed solutions for chip-to-chip optical interconnects. These efforts have demonstrated very low power consumption (and energy-per-bit) as well as single volt drive, which makes these devices compatible with current complementary metal oxide semiconductor (CMOS) drive voltages. Even lower drive voltages have been proposed for devices operating in forward bias (although they pull a direct current).
An advantage of low drive voltage is that while the International Technology Roadmap for Semiconductors (ITRS) predicts transistor supply voltage (Vdd) levels to drop below 710 my in 2019, recent work has suggested that in order to reduce power in exascale supercomputers to reasonable levels, transistor supply voltages may need to be lower than ITRS predictions. Chip supply rail levels of 500 mV are a possibility, and demonstrations have shown logic gates that can be run with Vdd as low as 350 mV. In order for optics to function with the low drive voltages proposed and the lower power demanded by exascale data centers and high performance computing (HPC) applications, both low voltage and low power are desired. It is possible to obtain low voltage and low power in reverse biased photonic devices.
For exascale computing applications, viable optical solutions are desired to operate using low voltage signaling and with low power consumption.